JPH11131052A - Seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a seal neither releasing a foreign matter to a space to be sealed nor requiring strong power for fastening. SOLUTION: This seal has a jacket 3 made of a metal with an opening part 31 for preventing a substance generated from a core member from transferring to a space to be sealed on the core member made of an elastic organic polymer such as an O-ring 2. The seal is useful as a vacuum seal and is capable of miniaturizing and lightening a vacuum apparatus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal, and more particularly to a ring-shaped seal suitable as a vacuum seal.

[0002]

2. Description of the Related Art In the field of semiconductors, since the presence of foreign substances is extremely disliked, a seal ring which does not emit gas or particles is required as a ring-shaped vacuum seal in this field. Conventionally, rubber O-ring, metal O as seal ring
Rings and C-rings with coil springs are well known. Of these, the rubber O-ring emits gas and particles, and thus is not suitable as a vacuum seal ring. Metal O-rings, on the other hand, can be used as vacuum seals if they are thoroughly cleaned before use because they do not release such foreign substances, but on the other hand, they must be tightened tightly to achieve a sufficient sealing function. Therefore, a large tightening mechanism capable of providing a sufficient tightening force is required, and as a result, there is a problem that the size of the vacuum device is increased.

A C-ring containing a coil spring has a structure in which a helical coil made of a hard metal such as stainless steel is housed in a jacket having a C-shaped cross section, as disclosed in, for example, Japanese Utility Model Laid-Open No. 63-92870. Since the ring is made of metal, it has the advantage that no foreign matter is released if it is sufficiently cleaned before use, as in the case of the metal O-ring, and the tightening force is not as large as that of the metal O-ring. However, even in this C-ring containing a coil spring, a large force is still required for compressing the internal helical coil, so that the tightening mechanism is relatively large, and there is a problem that the vacuum apparatus also becomes large.

[0004]

SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a seal which does not discharge foreign matter into a sealed space and does not require a large force for tightening.

[0005]

The present invention is characterized by having the following means in order to solve the above-mentioned problems. (1) A seal having a metal jacket having an opening on a core member made of an elastic organic polymer to prevent a substance generated from the core member from migrating into a sealed space and having an opening. (2) The seal according to the above (1), further comprising means for preventing the core member from being exposed from the opening when the metal jacket is tightened in a direction to close the opening. (3) The seal according to the above (1) or (2), wherein the metal jacket has a lip on an outer surface thereof for improving sealing properties. (4) The seal according to any one of (1) to (3) above, wherein the core member is an O-ring made of an elastic organic polymer, and the seal has a ring shape. (5) The lip has its apex parallel to the pressure receiving surface of the seal in the O-ring cross-section and the projection position on the normal existing on the opening side is 0.2r to 0.7r (r
Is the radius of the O-ring).

[0006]

In the present invention, a core member made of an elastic organic polymer,
For example, an O-ring is used, but even if gas or particles are released from the core member, they are prevented from migrating into a sealed space such as a vacuum device of a semiconductor manufacturing plant by a metal jacket. The metal jacket is
Due to the opening, the opening itself is deformed by a relatively small tightening force in a direction in which the opening is closed, and the compressive force of the elastic organic polymer core member is also reduced by the helical winding inside the metal O-ring or the C-ring containing a coil spring. Since it is smaller than those of the coil, the tightening force of the entire seal is also small.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a top view of the embodiment of the present invention in an unfastened state, FIG. 2 is a cross-sectional view taken along line XX of FIG. 1, and FIG. 3 is a view of the embodiment of FIG. 1 is a cross-sectional view taken along line XX of FIG. FIG. 4 is a top view of another embodiment of the present invention in an unfastened state, and FIG. 5 is a cross-sectional view taken along line XX of FIG. FIG. 6 is a top view of yet another embodiment of the present invention in an unfastened state, and FIG. 7 is a cross-sectional view taken along line XX of FIG. FIG.
FIG. 6 is a partially enlarged sectional view of FIG. 5.

1 to 8, reference numeral 1 denotes a ring-shaped seal, 2 denotes an O-ring formed of an elastic organic polymer, 3 denotes a metal jacket, and 31 denotes an opening of the metal jacket 3. 4 to 8, reference numeral 4 denotes a metal jacket 3.
Are provided on the outer surface of the lip.

In the embodiment shown in FIGS. 1 to 3, the metal jacket 3 has a U-shaped cross section, and the O-ring 2 is housed in the U-shaped recess. When this seal 1 is installed at a predetermined location of a vacuum device (not shown) and tightened from above and below in the direction of the arrow shown in FIG. 2 from the untightened state, the U-shaped cross section of the metal jacket 3 as shown in FIG. At the same time, the opening interval of the opening 31 becomes smaller, and at the same time, the cross-sectional shape of the O-ring 2 in the U-shaped recess is flattened as shown. Thus, a good sealing effect is produced by the internal stress generated due to the deformation of the O-ring 2 and the metal jacket 3, that is, the repulsive force. At this time, the inner side surface 32 of the metal jacket 3 (see FIGS. 1 and 3) may be exposed to the sealed space of the vacuum device, but the opening 31 of the metal jacket 3 or the outside of the metal jacket 3 may be exposed. Since the side surface 33 opens on the opposite side of the sealed space, in other words, toward the outside of the vacuum device, the metal jacket 3 is opened.
The O-ring 2 in the U-shaped recess is cut off from the sealed space of the vacuum device by the metal jacket 3.
Therefore, even if the O-ring 2 is made of an elastic organic polymer and emits a substance such as a cross-linking residue or other various volatile components and adsorbed gas, such gas and particles are removed by the metal jacket 3 to form a vacuum device. To the sealed space.

The embodiment shown in FIGS. 4 and 5 and the embodiment shown in FIGS. 6 and 7 are different from the embodiment shown in FIGS. 1 to 3 in that the lip 4 provided on the outer surface of the metal jacket 3 is different from the embodiment shown in FIGS. It differs in having. In the embodiment of FIGS. 4 and 5, the lip 4 has a triangular cross section and is provided in contact with the outer surface 33 of the metal jacket 3. On the other hand, in the embodiment shown in FIGS. 6 and 7, the lip 4 has the same triangular cross section, but is provided at a position slightly away from the outer surface 33 of the metal jacket 3. In the present invention, such a lip 4 is not essential, but it is pressed against a surface to be sealed, such as an inner surface of a groove in which the seal 1 is installed, and functions to enhance the sealing effect. 4 and 5
The embodiment shown in FIG. 6 and the embodiment shown in FIGS. 6 and 7 are deformed basically in the same manner as the embodiment shown in FIGS.

Next, preferred structures and dimensions of the present invention will be described with reference to FIG. In FIG. 8, r is the radius of the O-ring 2, T1 is the thickness of the tip of the metal jacket 3,
T2 is the thickness of the U-shaped bottom of the metal jacket 3, L is the Y-Y line passing through the center point M of the O-ring 2 and the metal jacket 3
T, e, H, W, and θ are the vertices of the lip 4 and the point where the positions of the vertices t are projected on the illustrated normal line a in the O-ring 2 and the height, respectively. , Base length, and vertex angle at vertex t.

The radius r of the O-ring 2 varies depending on the purpose of use of the seal of the present invention, the size of a device requiring the seal, and the like. However, when the seal of the present invention is applied to a normal vacuum device, For example, it is about 0.5 to 5 mm. The thicknesses T1 and T2 of the metal jacket 3 slightly vary depending on the kind of metal forming the jacket, particularly, hardness, elastic modulus, and the like, but are generally about 0.2r to 1.5r. FIG. 8 illustrates a case where T1 and T2 are equal to each other and also equal to r. In the present invention,
T1 and T2 need not be equal to each other,
Rather, it is possible to adjust or adjust the tightening force of the seal 1 with different thicknesses.

The YY line and the outer surface 3 of the metal jacket 3
When the length L up to 3 is too small, for example, zero, that is, when the outer surface 33 of the metal jacket 3 is on the YY line, the O-ring 2 is compressed by the metal jacket 3 when the seal 1 is tightened. Instead, they may go outside through the opening 31. Therefore, the length L is preferably at least about 0.1r, particularly preferably at least about 0.2r, and more preferably about 0.2r to 1.5r. FIG. 8 illustrates a case where L is equal to r. In the present invention, the above-described length L of the metal jacket 3 functions as one means for preventing the O-ring 2 from being exposed from the opening. In addition, as another means for preventing the protrusion from the opening of the O-ring 2, a protrusion for preventing protrusion is provided on the inner wall of the U-shaped recess of the metal jacket 3, a tip of the U-shaped recess is slightly bent inward, and a U-shaped C instead of depression
It may be a letter-shaped depression.

In the present invention, the installation position of the lip 4 is not particularly limited. However, it is shown in FIG.
If it is provided on the side closer to the inner side surface 32 of the metal jacket 3 than the line, when the seal is tightened, the O-ring 2
Tends to eat out from the sea. On the other hand, if the lip 4 is brought too close to the outer surface 33 of the metal jacket 3,
The sealing effect produced when the seal is tightened tends to be poor. Therefore, the lip 4 is installed at a projection position e on a normal a of the vertex t (a normal parallel to the pressure receiving surface OS of the seal 1 in the cross section of the O-ring 2 and present on the opening 31 side). Is 0.2r or more from the center point M of the O-ring 2.
It is preferably in the range of about 0.7r, especially about 0.3r to 0.6r. FIG. 8 illustrates a case where the projection position e of the vertex t on the normal a is 0.5 r from the center point M of the O-ring 2.

If the height H and the bottom length W of the lip 4 are too small, the effect of the lip installation is poor, while if they are too large, the tightening force of the seal and, consequently, the sealing function are unstable. Therefore, the height H is preferably about 0.2r to 0.7r, particularly about 0.3r to 0.6r, while the length W of the base is about 0.3r to 2r, particularly 0.5r to 1.r. 6
r is preferable. FIG. 8 illustrates a case where the height H is 0.5r and the length W of the base is 1r. Also lip 4
Is preferably about 50 to 130 °, particularly preferably about 60 to 110 °.

The cross-sectional shape of the lip 4 may be a semicircle, a semi-ellipse, or various other protrusion shapes other than the above-described triangle. The installation position, height, base length, and the like of the lip other than the triangle can be easily grasped by referring to the case of the triangle and performing some trial and error as necessary.

The elastic organic polymer forming the O-ring 2 includes natural rubber, ethylene propylene rubber, ethylene propylene diene rubber, acrylonitrile butadiene rubber, hydrogenated acrylonitrile butadiene rubber,
Rubbers such as styrene / butadiene rubber, silicone rubber, chloroprene rubber, chlorosulfonated polyethylene rubber, fluororubber, fluorinated silicone rubber, acrylic rubber, ethylene acrylic rubber or their crosslinked rubbers, polystyrene-based thermoplastic elastomers, polyolefin-based heat Examples thereof include thermoplastic elastomers such as a thermoplastic elastomer, a polyvinyl chloride-based thermoplastic elastomer, and a polyester-based thermoplastic elastomer. Particularly, those which do not show a crystal melting point on a differential calorimetric curve in a DSC (differential scanning calorimeter) are preferable. is there.

The O-ring 2 may contain an antioxidant, an antioxidant, a reinforcing agent such as carbon black, a filler such as talc and clay, a cross-linking agent,
Chemicals commonly used in the production of the elastic organic polymer O-ring 2, such as a crosslinking aid, a crosslinking accelerator, and a processing aid, are blended in a usual amount, and the obtained composition is produced by a method such as press molding or injection molding. can do. O-ring 2 made of cross-linked rubber
It is crosslinked by heating in a molding process such as press molding or injection molding.

As described above, the O-ring 2 made of an elastic organic polymer has a remarkably small compressive force as compared with the helical coil used for the C-ring containing a coil spring. It can be used in the invention. However, among them, those having a Shore A hardness of about 60 to 100, particularly about 70 to 90 are preferable.

As the metal forming the metal jacket 3, various metals are used, including those that are thermally, chemically, or mechanically unstable under the environment in which the seal is used. In particular, FIGS.
In the case of the metal jacket 3 having a U-shaped or similar cross-sectional shape as shown in FIG. 8, a soft metal whose opening can be reduced with a relatively small compressive force, for example, aluminum, an aluminum alloy, annealed copper Preferred are metals having relatively good workability, such as copper alloys and magnesium alloys, and metal-ceramic composites.

[0021]

EXAMPLES Hydrogenated acrylonitrile butadiene rubber 1
Using a composition comprising 80 parts by weight of carbon black, 10 parts by weight of a plasticizer, 3 parts by weight of a cross-linking agent, and 5 parts by weight of a cross-linking aid per 100 parts by weight, at a temperature of 180 ° C. and a cross-linking time of 4 minutes. The inner diameter of the ring is 55 mm and the sectional radius r is 1.
2 mm cross-linked nitrile O-ring (Shore A hardness: 8
0) was obtained. Then, a jacket made of pure aluminum having a purity of 99.5% by weight was applied on the O-ring, and FIGS.
A ring-shaped seal having the structure shown in FIGS. 5 and 8 was manufactured. The main detail dimensions of the seal are as follows. T1: 1.2 mm, T2: 1.2 mm, L: 1.0
mm, W: 1.2 mm, H: 0.6 mm, position of point e:
0.6 mm from center M. The force required to tighten the seal of the present invention to a height that is 70% of the seal height before tightening is about 15 kg / cm, which is the value of a stainless steel metal O-ring of the same size. Approximately 1/1 such as the weakest one and the usual USU coil spring C ring
0.

[0022]

As described above, the conventional vacuum seal requires a large force for tightening, and as a result, it is inevitable that the tightening mechanism and the weight of the vacuum device are increased in size and weight. On the other hand, the seal of the present invention is useful as a vacuum seal because it does not release foreign matter into the sealed space and does not require a large force for tightening, and it is possible to reduce the size and weight of the vacuum device. Become.

[Brief description of the drawings]

FIG. 1 is a top view of an embodiment of the present invention in an unfastened state.

FIG. 2 is a cross-sectional view taken along line XX of FIG.

1. FIG. 3 is a cross-sectional view of the embodiment of FIG.
It is sectional drawing which followed the -X line.

FIG. 4 is a top view of another embodiment of the present invention in an unclamped state.

FIG. 5 is a sectional view taken along line XX of FIG. 4;

FIG. 6 is a top view of yet another embodiment of the present invention in an unfastened state.

FIG. 7 is a sectional view taken along the line XX of FIG. 6;

FIG. 8 is a partially enlarged sectional view of FIG. 5;

[Explanation of symbols]

 Reference Signs List 1 ring-shaped seal 2 O-ring formed of elastic organic polymer 3 metal jacket 31 opening of metal jacket 3 4 lip

Claims (5)

[Claims] 1. A metal jacket having an opening on a core member made of an elastic organic polymer to prevent a substance generated from the core member from migrating into a sealed space. sticker. 2. The seal according to claim 1, wherein the metal jacket has means for preventing the core member from escaping from the opening when the metal jacket is tightened in a direction to close the opening. 3. The seal according to claim 1, wherein the metal jacket has a lip on an outer surface thereof for improving a sealing property. 4. The seal according to claim 1, wherein the core member is an O-ring made of an elastic organic polymer, and the seal has a ring shape. 5. A lip whose apex is parallel to the pressure receiving surface of the seal in the O-ring cross-section and whose projection position on a normal existing on the opening side is 0.2 r to 0.2 r from the center point of the O-ring.
5. The seal according to claim 4, wherein the seal is within a range of 0.7r (r is a radius of the O-ring).